Alport's syndrome

Abstract

Alport's syndrome (AS, OMIM 301050) is a hereditary disorder characterized by progressive renal failure, hearing impairment and ocular changes. It is clinically and genetically heterogeneous and in its natural history, renal disease progresses from microscopic haematuria to proteinuria, and finally to progressive renal insufficiency. AS is caused by an inherited defect in a type IV collagen, a structural material, expressed in many tissues that is essential for the normal function of different parts of the body. In most of cases, about the 85%, Alport's syndrome is X-linked and is originated by mutations in the COL4A5 gene. In the remaining cases, it may be inherited in either an autosomal recessive, or rarely in an autosomal dominant manner. Mostly, the condition is caused by mutations in the COL4A3 or COL4A4 genes. Coexisting mutations in COL4A3, COL4A4, COL4A5 or COL4A6 were found to cause an Alport's syndrome phenotype with digenic inheritance. Diagnosis of the condition is based on family history, clinical signs, and specific procedures such as a kidney biopsy. The diagnosis can be confirmed by genetic testing. Treatment may include use of a hearing aid, hemodialysis, and peritoneal dialysis to treat those with end-stage renal failure, and, as the last step, kidney transplantation. Firstly described by Arthur C. Alport's, in 1927, over the years it has become a pathology of high scientific interest. At the moment, thanks to advances in diagnostic techniques, it is possible to make an early diagnosis avoiding irreversible damages and life -threatening complications.

Keywords: Alport’s syndrome; chronic kidney disease; collagen IV genes; lenticonus.